The present invention relates to an applicator for ejecting material, and particularly to an applicator useful for use in ejecting dental impression material for making dental impressions.
Dental impression for cast restorations is often a very difficult procedure, especially when the tooth preparation finishing lines extend subgingivally, i.e., below the gum line. This is often the case where consideration has to be given to esthetics, retention, extent of carious destruction, and the like. To overcome the problem of replication of the subgingival area, different techniques have been employed for allowing the impression material to be carried to the bottom of the gingival pocket. These techniques include electrosurgery, copper band impressions, and the use of gingival retraction cords combined with the use of a syringe. However, these known techniques are time-consuming and often involve traumatizing of the gingival tissues, frequently causing bleeding. Such bleeding complicates the impression taking, often requiring the dentist to discontinue further work until the bleeding has stopped.
This bleeding has also an undesirable risk of infecting the dental personnel with blood-borne diseases, such as Hepatitis B or AIDS (Acquired Immune Deficiency Syndrome). In fact, it is known that doctors and dentists are infected by the Hepatitis B virus at a rate two or three times that of the public at large. This creates a high degree of apprehension on the part of the medical or dental personnel treating the patient, and may also affect the attitude and/or service of such personnel with respect to the patient in view of the possibility of infection by the patient.
An object of the present invention is to provide an applicator particularly useful in making dental impressions which reduces or avoids the above drawbacks.